瀚海文化大厦 华润:Ping的源代码 ——世界网络

Ping的源代码
#pragma pack(4)#define WIN32_LEAN_AND_MEAN#include#include#include#define ICMP_ECHO 8#define ICMP_ECHOREPLY 0#define ICMP_MIN 8 // minimum 8 byte icmp packet (just header)/* The IP header */typedef struct iphdr {unsigned int h_len:4; // length of the headerunsigned int version:4; // Version of IPunsigned char tos; // Type of serviceunsigned short total_len; // total length of the packetunsigned short ident; // unique identifierunsigned short frag_and_flags; // flagsunsigned char ttl;unsigned char proto; // protocol (TCP, UDP etc)unsigned short checksum; // IP checksumunsigned int sourceIP;unsigned int destIP;}IpHeader;//// ICMP header//typedef struct _ihdr {BYTE i_type;BYTE i_code; /* type sub code */USHORT i_cksum;USHORT i_id;USHORT i_seq;/* This is not the std header, but we reserve space for time */ULONG timestamp;}IcmpHeader;#define STATUS_FAILED 0xFFFF#define DEF_PACKET_SIZE 32#define MAX_PACKET 1024#define xmalloc(s) HeapAlloc(GetProcessHeap(),HEAP_ZERO_MEMORY,(s))#define xfree(p) HeapFree (GetProcessHeap(),0,(p))void fill_icmp_data(char *, int);USHORT checksum(USHORT *, int);void decode_resp(char *,int ,struct sockaddr_in *);void Usage(char *progname){fprintf(stderr,"Usage:\n");fprintf(stderr,"%s [data_size]\n",progname);fprintf(stderr,"datasize can be up to 1Kb\n");ExitProcess(STATUS_FAILED);}int main(int argc, char **argv){WSADATA wsaData;SOCKET sockRaw;struct sockaddr_in dest,from;struct hostent * hp;int bread,datasize;int fromlen = sizeof(from);int timeout = 1000;char *dest_ip;char *icmp_data;char *recvbuf;unsigned int addr=0;USHORT seq_no = 0;if (WSAStartup(MAKEWORD(2,1),&wsaData) != 0){fprintf(stderr,"WSAStartup failed: %d\n",GetLastError());ExitProcess(STATUS_FAILED);}if (argc <2 ) {Usage(argv[0]);}sockRaw = WSASocket (AF_INET,SOCK_RAW,IPPROTO_ICMP,NULL, 0,0);if (sockRaw == INVALID_SOCKET) {fprintf(stderr,"WSASocket() failed: %d\n",WSAGetLastError());ExitProcess(STATUS_FAILED);}bread = setsockopt(sockRaw,SOL_SOCKET,SO_RCVTIMEO,(char*)&timeout,sizeof(timeout));if(bread == SOCKET_ERROR) {fprintf(stderr,"failed to set recv timeout: %d\n",WSAGetLastError());ExitProcess(STATUS_FAILED);}timeout = 1000;bread = setsockopt(sockRaw,SOL_SOCKET,SO_SNDTIMEO,(char*)&timeout,sizeof(timeout));if(bread == SOCKET_ERROR) {fprintf(stderr,"failed to set send timeout: %d\n",WSAGetLastError());ExitProcess(STATUS_FAILED);}memset(&dest,0,sizeof(dest));hp = gethostbyname(argv[1]);if (!hp){addr = inet_addr(argv[1]);}if ((!hp) && (addr == INADDR_NONE) ) {fprintf(stderr,"Unable to resolve %s\n",argv[1]);ExitProcess(STATUS_FAILED);}if (hp != NULL)memcpy(&(dest.sin_addr),hp->h_addr,hp->h_length);elsedest.sin_addr.s_addr = addr;if (hp)dest.sin_family = hp->h_addrtype;elsedest.sin_family = AF_INET;dest_ip = inet_ntoa(dest.sin_addr);if (argc >2) {datasize = atoi(argv[2]);if (datasize == 0)datasize = DEF_PACKET_SIZE;}elsedatasize = DEF_PACKET_SIZE;datasize += sizeof(IcmpHeader);icmp_data = xmalloc(MAX_PACKET);recvbuf = xmalloc(MAX_PACKET);if (!icmp_data) {fprintf(stderr,"HeapAlloc failed %d\n",GetLastError());ExitProcess(STATUS_FAILED);}memset(icmp_data,0,MAX_PACKET);fill_icmp_data(icmp_data,datasize);while(1) {int bwrote;((IcmpHeader*)icmp_data)->i_cksum = 0;((IcmpHeader*)icmp_data)->timestamp = GetTickCount();((IcmpHeader*)icmp_data)->i_seq = seq_no++;((IcmpHeader*)icmp_data)->i_cksum = checksum((USHORT*)icmp_data,datasize);bwrote = sendto(sockRaw,icmp_data,datasize,0,(struct sockaddr*)&dest,sizeof(dest));if (bwrote == SOCKET_ERROR){if (WSAGetLastError() == WSAETIMEDOUT) {printf("timed out\n");continue;}fprintf(stderr,"sendto failed: %d\n",WSAGetLastError());ExitProcess(STATUS_FAILED);}if (bwrote < datasize ) {fprintf(stdout,"Wrote %d bytes\n",bwrote);}bread = recvfrom(sockRaw,recvbuf,MAX_PACKET,0,(struct sockaddr*)&from,&fromlen);if (bread == SOCKET_ERROR){if (WSAGetLastError() == WSAETIMEDOUT) {printf("timed out\n");continue;}fprintf(stderr,"recvfrom failed: %d\n",WSAGetLastError());ExitProcess(STATUS_FAILED);}decode_resp(recvbuf,bread,&from);Sleep(1000);}return 0;}/*The response is an IP packet. We must decode the IP header to locatethe ICMP data*/void decode_resp(char *buf, int bytes,struct sockaddr_in *from) {IpHeader *iphdr;IcmpHeader *icmphdr;unsigned short iphdrlen;iphdr = (IpHeader *)buf;iphdrlen = iphdr->h_len * 4 ; // number of 32-bit words *4 = bytesif (bytes < iphdrlen + ICMP_MIN) {printf("Too few bytes from %s\n",inet_ntoa(from->sin_addr));}icmphdr = (IcmpHeader*)(buf + iphdrlen);if (icmphdr->i_type != ICMP_ECHOREPLY) {fprintf(stderr,"non-echo type %d recvd\n",icmphdr->i_type);return;}if (icmphdr->i_id != (USHORT)GetCurrentProcessId()) {fprintf(stderr,"someone else's packet!\n");return ;}printf("%d bytes from %s:",bytes, inet_ntoa(from->sin_addr));printf(" icmp_seq = %d. ",icmphdr->i_seq);printf(" time: %d ms ",GetTickCount()-icmphdr->timestamp);printf("\n");}USHORT checksum(USHORT *buffer, int size) {unsigned long cksum=0;while(size >1) {cksum+=*buffer++;size -=sizeof(USHORT);}if(size ) {cksum += *(UCHAR*)buffer;}cksum = (cksum >> 16) + (cksum & 0xffff);cksum += (cksum >>16);return (USHORT)(~cksum);}/*Helper function to fill in various stuff in our ICMP request.*/void fill_icmp_data(char * icmp_data, int datasize){IcmpHeader *icmp_hdr;char *datapart;icmp_hdr = (IcmpHeader*)icmp_data;icmp_hdr->i_type = ICMP_ECHO;icmp_hdr->i_code = 0;icmp_hdr->i_id = (USHORT)GetCurrentProcessId();icmp_hdr->i_cksum = 0;icmp_hdr->i_seq = 0;datapart = icmp_data + sizeof(IcmpHeader);//// Place some junk in the buffer.//memset(datapart,'E', datasize - sizeof(IcmpHeader));}